Self-stripping wire twister hook for wire balers



w. K. RALSTON ET AL 3,400,653

SELF-STRIPPING WIRE TWISTER HOOK FOR WIRE BALERS Sept, 10, 1968 Filed Oct. 21. 1966 F/Gl.

m 2L; 3% avg J r G H W A,

m w m \\\\\\\\\w INVENTORS WILL/AM K.RALSTON PATRICK L.MA CHARLES e. BARF/EL Z/I %W ATTY United States Patent 3,400,653 SELF-STRIPPING WIRE TWISTER HOOK FOR WIRE BALERS William K. Ralston and Patrick L. May, Memphis, Tenn., and Charles G. Barfield, West Memphis, Ark., assignors to International Harvester Company, Chicago, 111., a corporation of Delaware Filed Oct. 21, 1966, Ser. No. 588,442 4 Claims. (Cl. 10031) This invention relates to a twisting mechanism of the general type used in hay balers and more particularly to an improvement in a twister hook for such twisting mechamsm.

The preferred embodiment of the present invention as disclosed herein contemplates that the novel twister hook be incorporated in a twisting mechanism of the type shown in the Raney Patent 2,513,967, issued July 4, 1950. In the twisting mechanism disclosed therein, .a twister hook is used for twisting the ends of a strand of wire encircling a bale formed in a baler. At the conclusion of the twisting phase, a stripper finger is actuated forcing the twisted wire from the hook. The use of a stripper finger as the means for stripping the twisted wire from the hook is undesirable because it increases the complexity of an already complex mechanism. For example, the stripper finger must be actuated at precisely the right moment in the sequence of twisting operation. This requires modification of the other components of the mechanism in order that the stripper finger coordinate therewith. Furthermore, the stripper finger must be precisely adjusted to travel far enough out to dislodge the twisted wire from the hook.

A general object of this invention is the provision of a self-stripping twister hook, that is, a hook that requires no additional equipment for dislodging the twisted wire therefrom, thereby reducing the complexity of the twisting mechanism and simplifying the twisting operation.

Another object of the present invention is to provide a wire twisting mechanism having a self-stripping twister hook.

Still another object is to provide a twister hook which is rotatable in a given plane for twisting and pivotable to a stripping position.

These and other objects of the present invention will become apparent to those skilled in the art as a preferred embodiment of the invention is disclosed in the following specification and claims taken in conjunction with the drawings in which:

FIGURE 1 is a fragmentary side view, partly in section, of the novel twister hook contemplated by the present invention showing the twister hook in the twisting position; and

FIGURE 2 is, similarly, a side view of the novel twister hook but shown in its stripping position.

The preferred embodiment of the present invention as disclosed herein shows the novel twister hook incorporated in a wire-twisting mechanism of the type shown in the previously mentioned Raney patent. However, it should be understood that this is for illustrative purposes only in order to show the environment in which the novel hook operates, and that the novel features of the hook may be employed in other twisting mechanisms.

Referring to FIGURE 1 the wire twister device constructed in accordance with the principle of the present invention comprises generally a twister hook 13 and a shaft 11 journalled to a housing 12. It should be noted that the housing 11 carries other components of the twisting mechanism with which the novel hook presented herein cooperates. One of such mechanisms is described in detail in the US. Patent 2,513,967.

One end 11a of the shaft 11 is flared forming a radial shoulder 20 which has an annular surface 20a engageable with a mating surface 12a formed in the housing 12. The end 11a of the shaft 11 also has formed therein an axial recess 14 for receiving a compression spring 15. One end 15:: of the compression spring 15 engages a flat radial surface 14a bottoming the recess 14, and an opposite end 15b carries a guide member 19. The guide member 19 is particularly sized for free axial movement within the confines of recess 14.

The hook 13 is pivotally mounted on the shoulder 20 by pin 21 and has integrally formed thereon a toe member 22 and a heel member 23. With reference to the axis of shaft 11, the toe member 22 and the heel member 23 respectively project radially outwardly and radially inwardly from the pivot point 21.

As shown in FIGURE 1, the toe member 22 carries loops 26c and 26d formed in strand ends 2611 and 26b, respectively. Rotation of the shaft 11 in accordance with the operation described in the previously mentioned patent causes the strand ends 26a and 26b to intertwist. Wire tension is borne by the toe member 22 at the point of engagement of the loops 26c and 26d thereupon.

The heel 23 has formed thereon an upwardly facing arcuate surface 24. The guide member 19 forcibly engages the arcuate surface 24 of the heel member 23 biasing the hook 13 in the twisting position as shown in FIG- URE 1 wherein a flat portion 24 of the hook 13 rests on a stop 25 formed in the shoulder 20.

Thus, it is seen that forces are applied on opposite sides of the pivot point 21. The strength of the compression spring 15 is particularly selected so that the moment of force created thereby acting upon the heel member 23 is always greater than that created by wire tension acting upon the toe member 22 during twisting operation.

At the conclusion of the twisting operation, the twister hook 23 occupies its home position, the toe member 22 projecting transversely with respect to the direction of movement of the bale encircled by strand 26. In the operation of a conventional baler, a succeeding bale forces the formed bale rearwardly increasing the wire tension in strand 26. The increased tension is brought to bear upon the toe member 22 through the engagement of loops 26c and 26d thereupon, increasing the moment of force about pivot point 21. At a predetermined wire tension, the moment of force acting on the toe member 22 exceeds that acting on the heel member 23 causing the hook 13 to pivot about pivot point 21.

The toe member 22 is pulled downwardly causing the heel member 23 to compress the compression spring 15 against recess bottom 14a. The force contact point between the guide member 19 and the arcuate surface 24 is always co-axial with respect to shaft 11 so that the forces are always transmitted in a direction concurrent the axis of shaft 11.

Pivotal movement continues as the wire tension increases until the hook is disposed in the stripping position as shown in FIGURE '2. It should be understood that the pivotal movement is not snap acting, but a gradual process thereby allowing the intertwisted ends 26a and 26b to be tightened as the wire tension increases.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A wire twisting mechanism for intertwisting opposite ends of a strand of wire encircling a bale formed in a baling machine, comprising a shaft rotatable about a fixed axis, a twister hook pivotally mounted on said shaft, said twister hook being pivotable about an axis between a first position for rotation and a second position for stripping wire therefrom, biasing means operative upon said twister hook in a direction lengthwise of said shaft axis for biasing the said twister hook in said first position for rotation.

2. In the mechanism recited in claim 1 wherein the twister hook includes a toe member and a heel member, said toe member projecting from said pivot axis radially outwardly with respect to said shaft axis, said heel member projecting from said pivot axis radially inwardly with respect to said shaft axis.

3. A wire twisting mechanism as recited in claim 2 wherein the said biasing means imparts a force upon said 4 heel member, thereby biasing the said twister hook in the said first position for rotation. r

4. A wire twisting mechanism as recited in claim 3 wherein the said biasing means includes a compression 5 spring disposed concentrically with said shaft.

References Cited UNITED STATES PATENTS I I 7/1950 Raney et al 100-22 1/1967 Grichnik 289-11 LOUIS O. MAASSEL, Primary Examiner. 

1. A WIRE TWISTING MECHANISM FOR INTERTWISTING OPPOSITE ENDS OF A STRAND OF WIRE ENCIRCLE A BALE FORMED IN A BALING MACHINE, COMPRISING A SHAFT ROTATABLE ABOUT A FIXED AXIS, A TWISTER HOOK PIVOTALLY MOUNTED ON SAID SHAFT, SAID TWISTER HOOK BEING PIVOTABLE ABOUT AN AXIS BETWEEN A FIRST POSITION FOR ROTATION AND A SECOND POSITION FOR STRIPPING WIRE THEREFROM, BIASING MEANS OPERATIVE UPON SAID TWISTER HOOK IN A DIRECTION LENGTHWISE OF SAID SHAFT AXIS FOR BIASING THE SAID TWISTER HOOK IN SAID POSITION FOR ROTATION. 